Rotary valve and cryogenic refrigerator using same

Abstract

A rotary valve includes a valve body and a valve plate. The valve body has a body-side passage formed therein, and includes a first slide surface. The valve plate has a plate-side passage formed therein, and includes a valve plate body and a resin valve slide body. The valve plate body is formed of a non-magnetic material and includes an accommodation room. The resin valve slide body is accommodated in the accommodation room of the valve plate body. The resin valve slide body includes a second slide surface in close contact with the first slide surface of the valve body. The valve plate rotates to switch a state of connection of the body-side passage and the plate-side passage.

1 . A rotary valve, comprising:
 a valve body having a body-side passage formed therein, the valve body including a first slide surface; and   a valve plate having a plate-side passage formed therein, the valve plate including
 a valve plate body formed of a non-magnetic material, the valve plate body including an accommodation room; 
 a resin valve slide body accommodated in the accommodation room of the valve plate body, the resin valve slide body including a second slide surface in close contact with the first slide surface of the valve body, wherein the valve plate rotates to switch a state of connection of the body-side passage and the plate-side passage. 
   
     
     
         2 . The rotary valve as claimed in  claim 1 , wherein the valve plate further comprises:
 a rotation prevention member configured to prevent a rotation of the valve slide body relative to the valve plate body.   
     
     
         3 . The rotary valve as claimed in  claim 1 , wherein the valve slide body is configured to be detached from and reattached to the valve plate body. 
     
     
         4 . The rotary valve as claimed in  claim 1 , wherein the valve body is formed of a magnetic material. 
     
     
         5 . A cryogenic refrigerator, comprising:
 a gas compressor configured to compress a refrigerant gas taken in from an inlet port and to discharge the compressed refrigerant gas from an outlet port;   a cylinder configured to be fed with the refrigerant gas;   a displacer configured to reciprocate in the cylinder to expand the compressed refrigerant gas in the cylinder;   a drive unit configured to cause the displacer to reciprocate in the cylinder; and   a rotary valve,   the rotary valve including
 a valve body having a first body-side passage and a second body-side passage formed therein, the first body-side passage being connected to the outlet port and the second body-side passage being connected to the cylinder, the valve body including a first slide surface; and 
 a valve plate having a plate-side passage formed therein, the plate-side passage being connected to the inlet port, the valve plate including
 a valve plate body formed of a non-magnetic material, the valve plate body including an accommodation room; 
 a resin valve slide body accommodated in the accommodation room of the valve plate body, the resin valve slide body including a second slide surface in close contact with the first slide surface of the valve body, wherein the valve plate rotates to cause the second body-side passage to be connected selectively to one of the first body-side passage and the plate-side passage.